The aim of this proposed research is to compare and analyze the genetic components of olfactory behavior of generalized feeding species and specialized feeding species. Emphasis will be placed on alcohols as the olfactory cues. Two different genetic approaches will be taken in examining olfactory discrimination, chemotaxis and learning behavior in response to olfactory cues, These approaches are quantitative analysis and genetic dissection. Both approaches provide useful information in establishing degree and nature of the inheritance of complex behavior patterns. The quantitative analysis approach to studying behavioral traits that are controlled, by many genes is to subdivide the measured phenotypic variance into component parts genotypic and environmental components. Several types of experiments including directional selection experiments, diallel crosses, simplified triple test crosses, correlation approach, regression approach, and measures of repeatability will be done. The genetic components of olfactory behavior will be further analyzed by means of genetic dissection. This method involves fractionating the behavior into component parts and localizing each genetic component to a specific chromosome by analyzing single mutations. Olfactory cues have been shown to play significant roles in determining food preference, oviposition site preference, and reproductive strategies in several species of Drosophila. However, the extent to which mechanisms underlying olfactory behavior are shared among species is unknown. If a species can discriminate odors and learn to avoid odors that induce stress upon prolonged exposure, fitness of such a species should increase. This study will compare olfactory behavior within and between four species of Drosophila. For the student, this study will provide first-hand experience with a variety of techniques utilized in behavioral genetics.